A new species of Cirolana Leach, 1818 (Crustacea, Isopoda, Cirolanidae) from the western Ross Sea, Antarctica, the first record of the genus from polar waters

Cirolana mclaughlinae n. sp. is described from specimens collected in the Ross Sea, Antarctica. The species is characterised by the head having a prominent anterior marginal ridge, lacking a rostrum, and being dorsally depressed; the posterior submarginal surfaces of perconites 5-7 and the pleonites are nodulose and pitted; the pleotelson has weakly concave lateral margins converging to a narrowly rounded apex, the dorsal surface is provided with a low, longitudinal median ridge. The genus has a world-wide distribution, but has hitherto not been recorded from polar waters, the previous most southerly record being at about 44 degrees S.